<![CDATA[Math Is Fun Forum / probability and counting??]]>2013-01-23T00:02:13ZFluxBBhttp://www.mathisfunforum.com/viewtopic.php?id=18852<![CDATA[Re: probability and counting??]]>Thank you]]>http://www.mathisfunforum.com/profile.php?id=1959902013-01-23T00:02:13Zhttp://www.mathisfunforum.com/viewtopic.php?pid=249670#p249670<![CDATA[Re: probability and counting??]]>Hi;

You do not have to do much counting. Spot the pattern works well here.

I am getting 4.5 x 10 ^19 numbers.

]]>http://www.mathisfunforum.com/profile.php?id=337902013-01-22T01:24:26Zhttp://www.mathisfunforum.com/viewtopic.php?pid=249524#p249524<![CDATA[Re: probability and counting??]]>That doesn't help, I knew that just that i keep losing count.]]>http://www.mathisfunforum.com/profile.php?id=1959902013-01-21T21:25:37Zhttp://www.mathisfunforum.com/viewtopic.php?pid=249449#p249449<![CDATA[Re: probability and counting??]]>I could only figure out that there's at least .]]>http://www.mathisfunforum.com/profile.php?id=1962942013-01-21T18:42:14Zhttp://www.mathisfunforum.com/viewtopic.php?pid=249443#p249443<![CDATA[probability and counting??]]>How many 20-digit numbers are such that the sum of their digits is even?]]>http://www.mathisfunforum.com/profile.php?id=1959902013-01-21T17:13:22Zhttp://www.mathisfunforum.com/viewtopic.php?pid=249441#p249441